1. Technical Field
The invention concerns an apparatus for optically determining the profile and/or the upper surface properties of flat workpieces in a wide belt abrading machine.
2. Background Art
A belt abrading machine is known, from DE 32 02 104 A1, which has a presser bar extending transversely to the advancement direction of a workpiece and having a number of presser shoes arranged next to one another for pressing the abrading belt onto the upper surface of the workpiece. In it the pressing force of each presser shoe is individually controllable in dependency on the contours of the workpieces on a transport belt running under the abrading belt. For this the workpieces are sensed by means of detectors, for example non-contactingly by laser light fences. The detectors are arranged next to one another transversely to the transport direction of the workpieces, with each presser shoe of the presser bar having several detectors arranged in a row with it.
The optical detectors allow a better resolution than mechanical scanner elements, are however expensive in their multiplicity, and under the operating conditions of an abrading machine are capable of being disturbed by the yielded abrasion dust.